Revisiting the relationship of dynamic and resilient modulus test for asphaltic concrete mixtures Yasir Ali a,⇑ , Muhammad Irfan b , Muhammad Zeeshan a , Imran Hafeez c , Shafeeq Ahmed d a National Institute of Transportation, School of Civil and Environmental Engineering, National University of Sciences & Technology (NUST), Islamabad 44000, Pakistan b Military College of Engineering, National University of Sciences & Technology (NUST), Risalpur 24080, Pakistan c Department of Civil Engineering, University of Engineering & Technology, Taxila 47050, Pakistan d Highway Research and Training Centre, Burhan Camp Jallo 14400, Pakistan highlights  A correlation of |E / | and M R is developed.  Developed correlation is rigorously testing.  Developed correlation is compared with an existing correlation.  A statistical model for predicting |E / | as function of M R , gradation and mix volumetric parameter is presented. article info Article history: Received 10 January 2018 Received in revised form 9 March 2018 Accepted 12 March 2018 Keywords: Asphalt mixtures Resilient modulus Dynamic modulus Correlation Statistical model abstract Mechanistic-Empirical Pavement Design is considered relatively more effective than conventional empir- ical design for excessive tyre pressure exerted by axle load spectra and diverse environmental conditions. Many highway agencies are adopting a paradigm shift to Mechanistic-Empirical pavement design prac- tices, obsoleting huge inventories of resilient modulus database used for empirical design. This paper attempts to develop an empirical correlation of dynamic modulus (|E / |) and resilient modulus (M R )– two performance tests used to characterize the stiffness of asphaltic concrete mixtures, and proposes a statistical model for |E / | as a function of M R , gradation parameter, and mix volumetric parameter. For the comparison purpose, a rigorous testing using bi-level testing protocol is offered for all the relation- ships (i.e., correlation and model). The comparison of |E / | with M R shows that at a temperature of 25 °C, |E / | at 5 Hz is strongly correlated with M R at a loading frequency of 300 ms. The developed statistical model captured 97% of the variability in the data in predicting |E / | from M R with an error of 6% and 23% for first and second level of bi-level testing protocol, respectively. It is envisaged that the findings of this study can help the highway agencies and practitioners in smooth transitioning to Mechanistic-emprical pavement design practices. Ó 2018 Elsevier Ltd. All rights reserved. 1. Introduction Mechanistic-Empirical Pavement Design Guide (M-EPDG) for new and rehabilitated flexible pavement structures is considered more appropriate for improved pavement design practices with an enhanced capability for prediction of pavement performance and maintenance needs over the service life. Prior to M-EPDG, the American Association of State Highway and Transportation Officials (AASHTO) 1993 flexible pavement guide [1] was most widely used, which is inherently empirical and inadequate for heavy axle loads, tyre pressures, diverse environmental conditions, material variation, etc. This design guide uses resilient modulus (M R ) while M-EPDG uses |E / |. In order to shift smoothly from pre- vious design guide to new M-EPDG and save time and expenditure involved in performing laborious tests, a relationship of |E / | and M R is needed which can predict |E / | from M R . For this purpose, there exists a few correlation in the literature, however, these correla- tions are not rigorously tested. Therefore, this study revisits the relationship of |E / | and M R and attempts of improve the accuracy of this relationship so that it can used for prediction purpose. For the design of flexible pavements using M-EPDG, one of the key input parameters is the dynamic modulus (|E / |)–a parameter https://doi.org/10.1016/j.conbuildmat.2018.03.098 0950-0618/Ó 2018 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail addresses: yasirali@nit.nust.edu.pk (Y. Ali), mirfan@mce.nust.edu.pk (M. Irfan). Construction and Building Materials 170 (2018) 698–707 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat